4A buck converter in a 2x3 mm package
The 2.5 MHz switching frequency lets you use small 1 µH inductors and 10 µF ceramic output capacitors, shrinking the total solution footprint around the 11-VFQFN-HR (2x3) package.
Switching frequency and inductor sizing
At 2.5 MHz the converter stays above the AM band, which simplifies EMI filtering in noise-sensitive equipment. The high frequency also means the inductor ripple current is low enough that a 1 µH rated for 4 A saturation handles the full load without excessive core loss.